Update quota surface to support prefetching.

Also includes attribute protocol definitions for 'duration'

Author: Martin Taillefer

mixer/v1/attributes.proto

@@ -16,6 +16,7 @@ syntax = "proto3";
 
 package istio.mixer.v1;
 
+import "google/protobuf/duration.proto";
 import "google/protobuf/timestamp.proto";
 
 // An instance of this message is delivered to the mixer with every
@@ -98,9 +99,10 @@ message Attributes {
   map<int32, double> double_attributes = 6;
   map<int32, bool> bool_attributes = 7;
   map<int32, google.protobuf.Timestamp> timestamp_attributes = 8;
-  map<int32, bytes> bytes_attributes = 9;
+  map<int32, google.protobuf.Duration> duration_attributes = 9;
+  map<int32, bytes> bytes_attributes = 10;
 
   // Attributes that should be removed from the specified attribute context. Deleting
   // attributes which aren't currently in the attribute context is not considered an error.
-  repeated int32 deleted_attributes = 10;
+  repeated int32 deleted_attributes = 11;
 }

mixer/v1/config/descriptor/quota_descriptor.proto

@@ -16,6 +16,9 @@ syntax = "proto3";
 
 package istio.mixer.v1.config.descriptor;
 
+import "google/protobuf/duration.proto";
+import "mixer/v1/config/descriptor/label_descriptor.proto";
+
 // Configuration state for a particular quota.
 //
 // Quotas are similar to metrics, except that they are mutated through method
@@ -26,34 +29,25 @@ package istio.mixer.v1.config.descriptor;
 // A given quota is described by a set of attributes. These attributes represent
 // the different dimensions to associate with the quota. A given quota holds a
 // unique value for potentially any combination of these attributes.
-//
-// The quota kind controls the general behavior of the quota. An allocation
-// quota is only adjusted through explicit method calls. A rate limit quota's
-// values are reset to 0 automatically at a fixed interval.
 message QuotaDescriptor {
   // The name of this descriptor.
   string name = 1;
 
-  // A optional concise name for the quota, which can be displayed in user interfaces.
-  // Use sentence case without an ending period, for example "Request count".
+  // An optional concise name for the quota which can be displayed in user interfaces.
   string display_name = 2;
 
-  // An optional description of the quota, which can be used in documentation.
+  // An optional description of the quota which can be used in documentation.
   string description = 3;
 
-  // The name of the attribute that supplies the amount for a given
-  // quota allocation or release operation.
-  string amount_attribute = 4;
-
-  // The set of attributes that are necessary to describe a specific value cell
+  // The set of labels that are necessary to describe a specific value cell
   // for a quota of this type.
-  repeated string attributes = 5;
+  repeated LabelDescriptor labels = 4;
 
   // The default imposed maximum amount for values of this quota.
-  int64 max_amount = 6;
+  int64 max_amount = 5;
 
   // The amount of time allocated quota remains valid before it is
   // automatically released. If this is 0, then allocated quota is
   // not automatically released.
-  int32 expiration_seconds = 7;
+  google.protobuf.Duration expiration = 6;
 }

mixer/v1/quota.proto

@@ -16,7 +16,8 @@ syntax = "proto3";
 
 package istio.mixer.v1;
 
-import "google/rpc/status.proto";
+import "google/protobuf/duration.proto";
+import "google/protobuf/timestamp.proto";
 import "mixer/v1/attributes.proto";
 
 message QuotaRequest {
@@ -28,32 +29,18 @@ message QuotaRequest {
 
   // Used for deduplicating quota allocation/free calls in the case of
   // failed RPCs and retries. This should be a UUID per call, where the same
-  // UUID is used for retries of the same quota allocation or release call.
-  string deduplication_id = 4;
-
-  enum OperationKind {
-    QUOTA_MODE_UNSPECIFIED = 0;
-
-    // Allocate the specified amount, fail if insufficient resources available.
-    ALLOC_NORMAL = 1;
-
-    // Allocate from 0 to the specified amount, never fails.
-    ALLOC_BEST_EFFORT = 2;
-
-    // Release from 0 to the specified amount, never fails.
-    RELEASE_BEST_EFFORT = 3;
-  }
+  // UUID is used for retries of the same quota allocation call.
+  string deduplication_id = 3;
 }
 
-// Used to update quota values before and/or after performing an action.
-//
-// A common use case for quotas is to implement rate limits within a service.
-// Quotas can also be used to impose upper limits on the number of specific
-// resources exposed by a service to its consumers.
 message QuotaResponse {
   // Index of the request this response is associated with
   int64 request_index = 1;
 
-  // Indicates whether or not the quota operation succeeded.
-  google.rpc.Status result = 2;
+  // The time at which the returned quota expires
+  google.protobuf.Timestamp expiration = 2;
+
+  // The total amount of quota returned, can be used to satisfy
+  // quota requests with matching attributes until the given expiration time.
+  int64 amount = 3;
 }